Helping people with computers... one answer at a time.

Flash memory is not the same as the type of memory used as your system RAM. They have different characteristics and they're accessed differently.

Can I use a USB RAM stick to increase system memory?

No.

That was simple. But to avoid this becoming the shortest Ask Leo! article ever, let me explain why.

As you can probably guess by now, all memory is not created equal. Your system memory typically resides on your computer's motherboard, and uses a very high speed interface to connect to your computer's CPU. In fact, as fast as that interface is, it's still not as fast as we would like it (so true about so many things), and most modern CPUs actually copy or "cache" blocks of memory internally where they can access it even faster.

One of the characteristics of system memory is that when you remove power, *poof*, the memory has lost whatever it contained. Time to reboot.

"The downside to flash RAM is that it's slower."

USB Memory Sticks, on the other hand, are expected to retain whatever you put in them when the power is removed. Heck, they're expected to retain their memory when they're completely removed from the computer. As a result they use a different memory technology typically called "flash ram", which does exactly that. It's called "flash" because the memory contents are loaded, and then a special signal is sent that, in a sense, tells the memory to "remember this, now". It's kind of like taking a picture with a flash on your camera ... the picture "remembers" the state of everything when the flash went off. Flash BIOS is called that for the same reason - it's just flash memory that contains your computer's BIOS.

The downside to flash RAM is that it's slower. Reading flash memory is slower, and writing to flash memory is MUCH slower. It works fine as a virtual disk drive because our expectations for a disk's speed are quite different than what we expect for system memory.

In addition to the issue of the memory's own speed, there's also the USB interface to consider. As fast as it is for other purposes, it, too, is significantly slower than your system's main memory.

So USB RAM sticks, memory sticks, key chain drives, geek sticks, whatever you call them, are great for portable data storage. But increasing your system's memory is an entirely different proposition.

Article C2327 - April 9, 2005 « »

Share this article with your friends:

Share this article on Facebook Tweet this article Email a link to this article
Leo Leo A. Notenboom has been playing with computers since he was required to take a programming class in 1976. An 18 year career as a programmer at Microsoft soon followed. After "retiring" in 2001, Leo started Ask Leo! in 2003 as a place for answers to common computer and technical questions. More about Leo.

Not what you needed?

Recent Comments
65 Comments
Boris C.
April 23, 2011 7:21 AM

Doesn't flash memory have limited writes? Using it as virtual memory will wear it out faster.

smartalec44
December 17, 2011 11:58 AM

If the RAM stick is so slow. why are people putting whole operating systems like Linux on them and booting into them at startup?

Slower than RAM (MUCH slower to write), but faster than a hard disk. It's a way to have an operating system run on your machine without having to install it to the HD.
Leo
17-Dec-2011
Lee Mcknight
April 10, 2012 10:29 PM

is there readyboost for windows xp and where can i find it.

Mark J
April 11, 2012 1:16 PM

@Lee
Readyboost was a feature Windows implemented with Vista and it doesn't exist on XP.

M.p.maletha
July 10, 2012 5:39 AM


Can I use extra RAM memory in my nokiaE5,as has USB installed in it. Pls. Gaid me.
I hope help me.